Classifications

• • G—PHYSICS
  • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
  • G21K—TECHNIQUES FOR HANDLING PARTICLES OR IONISING RADIATION NOT OTHERWISE PROVIDED FOR; IRRADIATION DEVICES; GAMMA RAY OR X-RAY MICROSCOPES
  • G21K1/00—Arrangements for handling particles or ionising radiation, e.g. focusing or moderating
  • G21K1/08—Deviation, concentration or focusing of the beam by electric or magnetic means
• • G—PHYSICS
  • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
  • G21K—TECHNIQUES FOR HANDLING PARTICLES OR IONISING RADIATION NOT OTHERWISE PROVIDED FOR; IRRADIATION DEVICES; GAMMA RAY OR X-RAY MICROSCOPES
  • G21K5/00—Irradiation devices
  • G21K5/04—Irradiation devices with beam-forming means
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J1/00—Details of electrodes, of magnetic control means, of screens, or of the mounting or spacing thereof, common to two or more basic types of discharge tubes or lamps
  • H01J1/02—Main electrodes
  • H01J1/30—Cold cathodes, e.g. field-emissive cathode
  • H01J1/304—Field-emissive cathodes
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J3/00—Details of electron-optical or ion-optical arrangements or of ion traps common to two or more basic types of discharge tubes or lamps
  • H01J3/02—Electron guns
  • H01J3/021—Electron guns using a field emission, photo emission, or secondary emission electron source
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
  • H01J37/02—Details
  • H01J37/04—Arrangements of electrodes and associated parts for generating or controlling the discharge, e.g. electron-optical arrangement or ion-optical arrangement
  • H01J37/06—Electron sources; Electron guns
  • H01J37/065—Construction of guns or parts thereof
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
  • H01J37/02—Details
  • H01J37/04—Arrangements of electrodes and associated parts for generating or controlling the discharge, e.g. electron-optical arrangement or ion-optical arrangement
  • H01J37/06—Electron sources; Electron guns
  • H01J37/073—Electron guns using field emission, photo emission, or secondary emission electron sources
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
  • H01J37/02—Details
  • H01J37/04—Arrangements of electrodes and associated parts for generating or controlling the discharge, e.g. electron-optical arrangement or ion-optical arrangement
  • H01J37/10—Lenses
  • H01J37/12—Lenses electrostatic
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J9/00—Apparatus or processes specially adapted for the manufacture, installation, removal, maintenance of electric discharge tubes, discharge lamps, or parts thereof; Recovery of material from discharge tubes or lamps
  • H01J9/02—Manufacture of electrodes or electrode systems
  • H01J9/022—Manufacture of electrodes or electrode systems of cold cathodes
  • H01J9/025—Manufacture of electrodes or electrode systems of cold cathodes of field emission cathodes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B33—ADDITIVE MANUFACTURING TECHNOLOGY
  • B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
  • B33Y80/00—Products made by additive manufacturing
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J2201/00—Electrodes common to discharge tubes
  • H01J2201/30—Cold cathodes
  • H01J2201/304—Field emission cathodes
  • H01J2201/30403—Field emission cathodes characterised by the emitter shape
  • H01J2201/30407—Microengineered point emitters
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J2237/00—Discharge tubes exposing object to beam, e.g. for analysis treatment, etching, imaging
  • H01J2237/06—Sources
  • H01J2237/061—Construction
  • H01J2237/062—Reducing size of gun
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J2237/00—Discharge tubes exposing object to beam, e.g. for analysis treatment, etching, imaging
  • H01J2237/06—Sources
  • H01J2237/063—Electron sources
  • H01J2237/06325—Cold-cathode sources
  • H01J2237/06341—Field emission
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J2237/00—Discharge tubes exposing object to beam, e.g. for analysis treatment, etching, imaging
  • H01J2237/06—Sources
  • H01J2237/063—Electron sources
  • H01J2237/06375—Arrangement of electrodes
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J2237/00—Discharge tubes exposing object to beam, e.g. for analysis treatment, etching, imaging
  • H01J2237/10—Lenses
  • H01J2237/12—Lenses electrostatic
  • H01J2237/1205—Microlenses
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J2237/00—Discharge tubes exposing object to beam, e.g. for analysis treatment, etching, imaging
  • H01J2237/10—Lenses
  • H01J2237/12—Lenses electrostatic
  • H01J2237/1207—Einzel lenses

Definitions

• This invention relates generally to highly miniaturized electron beam sources, and particularly to sub-nanometer-scale electron beam sources and systems, fabrication methods
• sub-nanometer-scale electron beam designates an electron beam
• Small-scale electron beam sources and sub-nanometer-scale electron beam sources, systems, fabrication methods, and uses thereof in particular.
• Sources of these electron beams are often contained in the tips of the analytical device.
• Electron point sources which may be utilized in these analytical devices, are well known
• United States patent 5,654,548 (“Source for intense coherent electron pulses") discloses how such sources can be used for one type of electron microscopy. The entire disclosure of this United States patents is hereby incorporated by reference into this specification. Electron beams have been used in constructing microscopes. For example, United
• An electron beam microscope includes an electron beam pattern source, a vacuum
• the prior art sources of atomic point source electron beam emitters typically must be operated at very low pressures, on the order of about 10-8 to 10-10 Torr, to protect them from disruptive contamination, chemical degradation, or destructive ion bombardment by residual gas ions. This often requires the use of complicated, expensive, and cumbersome equipment.
• Carbon-based nanotubes may be configured as superconducting nano-channels.
• Nanotubes are resilient and have nanometer-scale, sharp tips. As such, they are useful for making micro-probe tips of microscopy devices, e.g., scanning tunneling microscope and atomic force microscope.
• the dimensions of carbon-based nanotubes ideally having a single atom at the tip apex, but typically being 3 to 10 atoms in diameter at the tip, allows the tip to
• This tunneling current is
• the barrier is the repulsive force of the Meissner effect between the superconducting carbon-based nanotube and substrate.
• the Meissner effect is the ability of a material in a superconducting state to expel all magnetic fields therefrom (i.e., such a superconductor is perfectly diamagnetic and exhibits a permeability of zero).
• nanotube refers to a hollow structure having a diameter of from about 0.3 to about 10 nanometers, and a length of from about 3 to about 10,000
• nanotubes In general, such nanotubes have aspect ratios of at least about 1 : 10 to about
• Carbon-based nanotubes are hollow structures composed between 95-tol00% of carbon atoms. In general, the most commonly studied forms of nanotubes have physical properties such that they conduct electricity better than copper. Typically, carbon nanotubes have tensile strength 100 times that of steel. Carbon nanotubes become superconductors at
• Nanotubes may be fabricated from materials other than carbon, e.g., Tungsten disulphide, Molybdenum disulphide, and Boron nitride. Carbon nanotubes may be capped with metallic cores. Carbon nanotubes can be doped with other elements, e.g. metals. Carbon-based nanotubes may be either single-walled nanotubes (SWNT) or multi- walled nanotubes (MWNT). A MWNT includes several nanotubes each having a different diameter. Thus, the smallest diameter nanotube is encapsulated by a larger diameter nanotube, which in turn, is encapsulated by another larger diameter nanotube.
• SWNT single-walled nanotubes
• MWNT multi- walled nanotubes
• a MWNT includes several nanotubes each having a different diameter. Thus, the smallest diameter nanotube is encapsulated by a larger diameter nanotube, which in turn, is encapsulated by another larger diameter nanotube.
• Carbon-based nanotubes are used to form superconducting nanochannels for steering
• field emitters discloses "Carbon cone and carbon whisker field emitters. These field emitters
• microscopy and field emission discloses "Forming micro-probe tips for an atomic force
• microscope a scanning tunneling microscope, a beam electron emission microscope, or for
• Electron transparent nano-membranes are well known to those skilled in the art.
• channels comprising carbon-based nanotubes, which are capable of guiding and manipulating charged particle beams for microscopy applications.
• the nano-electron-beam approach to these technologies involves greatly miniaturizing the electron-beam source system to microscopic, sub-micron dimensions by use
• an electron beam nano-lithography system for writing integrated circuit patterns on substrates
• Massively parallel nano-electron-beam sources may render electron beam
• Massively parallel nano-electron-beam SEM scanning electron microscopy
• individual SEMs or more limited numbers of parallel SEMs of microscopic size could be developed for
• processing e.g., welding, cutting, deposition
• nano-assembly operations e.g., welding, cutting, deposition
• nanostructures such as carbon nanotubes.
• Massively parallel nano-electron-beam sources may prove useful for ultra-high
• Massively parallel nano-electron-beam sources may prove useful for small, high resolution, high speed video displays.
• Nano-sources of nano-electron-beams hold intriguing potential for use in
• nanometer-scale electron beam emitter comprising a nano-tip electron emitter and tunnel emission junction formed on substrate, an initial electron beam extraction electrode, and an electron beam lens.
• nanometer-scale electron beam emitter comprising a nano-tip electron emitter and tunnel emission junction formed on substrate, an initial electron beam extraction electrode, and a
• Einzel lens for directing an electron beam, said lens comprising a lower primary electron
• Figure 1 is a schematic representation of an enclosed point source electron beam
• Figure 2 is a schematic representation of an enclosed point source electron beam
• Figure 3 is a schematic representation of an enclosed point source electron beam
• Figure 4 is a schematic representation of a miniature scanning electron microscope
• Figure 5 is a schematic representation of an electron beam focusing coupler for a
• Figure 6 is a schematic representation of a superconducting nano-channel Y junction
• Figure 7 is a schematic representation of a superconducting nano-channel Y junction
• Figure 8 is a schematic representation of a point source electron beam generator
• Figure 9 is a schematic representation of one embodiment of a device for guiding
• Figure 1 OA is a schematic representation of a side view of a superconducting nano-
• Figure 1OB is a top view of the representation of Figure 1OA taken along line 10B-
• Figures HA, HB, and HC are schematic representations of embodiments of
• Figure 12 is a schematic representation of a superconducting nano-channel having
• Figures 13A and 13B are schematic representations of embodiments of a superconducting nano-channel split in the axial direction;
• Figure 14 is a schematic representation of a superconducting nano-channel connected
• Figures 15 A, 15B, and 15C are schematic representations of embodiments of superconducting nano-channels split into unequal portions
• Figure 16A - 16D are schematic representations of embodiments of merging superconducting nano-channels
• Figure 17 is a schematic representation of a superconducting nano-channel Y- j unction
• Figure 18 is a schematic representation of a superconducting nano-channel with
• Figure 19 is a schematic representation of a superconducting nano-channel as a field ionizer.
• Figure 2OA - 2OC are schematic representations of a superconducting nano-channel as a component of an acoustic wave detector system.
• Figure 21 is a schematic representation of another embodiment of an enclosed point source electron beam generator
• Figure 22 is a schematic representation of another embodiment of an enclosed point source electron beam generator
• Figure 23 is a schematic representation of an enclosed pico-SEM (Scanning Electron
• FIG. 24A is a cross-sectional schematic representation (not to scale) of one embodiment of a solid state sub-nanometer-scale electron beam emitter of the present
• Figure 24B is a top view of the solid state sub-nanometer-scale electron beam emitter of Figure 24A, taken along the line 24B - 24B of Figure 24A;
• Figure 25 is a cross sectional schematic diagram of a conventional Einzel electrostatic focusing lens for focusing an electron beam passing therethrough;
• Figure 26A is a detailed cross sectional view of one embodiment of a "nano-sandwich Einzel" lens of the nano-emitter system of Figure 24A;
• Figure 26B is an axial cross sectional view of the lens of Figure 26A, taken along the line 26B - 26B of Figure 26A;
• Figure 26C is an axial cross sectional view of the lens of Figure 26A wherein the central electrode thereof is comprised of a plurality of segments.
• electron beam as used throughout this specification is meant to include any beam comprising charged particles as is known to those skilled in the art.
• the invention of this patent application comprises the structure
• the rest of the system may comprise conventional or, due to the very narrow
• An alternative means of generating very fine electron beams at low voltages (about 50 to 500 volts) from a conventional electron beam and coupling it to a superconducting nano- channel is also disclosed.
• Such beams can be used for the microscopy systems and vacuum microelectronic devices.
• Very fine electron beams from any of the above sources may be guided and/or manipulated by superconducting nano-channels.
• suitably oriented magnetic fields may be used to confine electron beams for some distance once they have been
• magnetic field system depending on system size and performance requirements, may employ
• Such scanning may for instance be implemented by any of the lateral scanning
• electro-mechanical scanning techniques that are used for scanning tunneling microscopes or atomic force microscopes, following common practices well known to those in the field.
• multi-walled superconducting carbon nanotubes may be utilized as well, as may be any other essentially atomically perfect nanotube structure, which, if not naturally superconducting, may be optionally externally coated with a thin film of superconducting material.
• the thin wall 12 is electron-transparent, i.e., electron beams may be passed through it without significant dispersion or attenuation, relative to the intended application. Electron
• transparency is a function of electron energy and the type and thickness of the thin wall material. Using means well known to those skilled in the art, the initial electron beam energy would be set for attaining an acceptable level of electron transparency for a particular thin
• Electron-transparent thin-walls and structures and materials comprising them are well known
• wall 12 is preferably a film that preferably has a thickness of from about 1 to about 50 nanometers. In one preferred
• film 12 consists essentially of silicon nitride, boron nitride, or diamond.
• the wall 12, in combination with wall 18, defines a chamber 16.
• the vacuum within chamber 16 is preferably greater than about 10 "7 Torr. In one aspect of this embodiment, the vacuum within chamber 16 is from about 10 "7 to about 10 "10 Torr.
• the vacuum within chamber 16 may be created by conventional means.
• the tip assembly 10 is placed within an ultra high vacuum chamber (not shown) during its manufacturing assembly process and chamber 16 is vacuum sealed to the electron transparent wall 12 thus enclosing an ultra high vacuum within chamber 16.
• the chamber 16 has a relatively small volume, of preferably less than about 1 cubic
• the chamber 16 has a volume of less than about 0.1 cubic
• the tip assembly 10 is utilized within a sample vacuum chamber 20 whose volume may be at least about 1 ,000 times as great as the
• the vacuum in chamber 20 may be substantially lower than
• the pressure in chamber 20 is typically at least about 10 to 1 ,000 times as great as the pressure within chamber 16.
• assembly 10 is disposed above sample 22 and can be moved, by means described elsewhere in this specification, so that it is closer to or further away from sample 22.
• extraction electrode assembly 24 is preferably disposed around chamber 16. Electrode
• assembly 24 is electrically connected to external voltage supply 26 by means of conductors 28 and 30.
• the extraction electrode assembly 24 is disposed within chamber 24.
• the extraction electrode assembly 24 is electrically charged to an electrical potential typically in the range 50 to 500 volts with respect to the field emission tip 32 (which is the mono-atomic point source of electron beam 34).
• tip assembly 10 may comprise either a single or multi walled carbon nanotube 32 or a tungsten mono-atomic point emitter (not shown).
• the extraction electrode assembly 24 may optionally be fashioned from a
• emission tip 32 is attached to an electrically insulating tip enclosure 36 to isolate the tip 32
• the beam extraction voltage preferably is selected
• the beam 34 can subsequently be accelerated or decelerated as
• Figure 2 illustrates another configuration of a tip assembly 50 in which tip 32 is in the
• tip 32 has a relatively small diameter, in
• the carbon nanotube may be any suitable material.
• the carbon nanotube may be any suitable material.
• the tip 32 is preferably embedded in a support structure
• single walled metallic-type carbon nanotube 44 of relatively larger diameter in the range,
• the support structure 42 to provide a means for creating an electrical potential difference
• the electron beam 34 emerges from the field
• An optional coating of material 48 which may optionally be superconducting, may be used for purposes of vacuum sealing, enhanced mechanical strength, or enhanced superconducting focusing of electron beam 34.
• coating 48 may be connected to the electrical lead 43 and is then used as an electron extraction electrode, instead of nanotube 44.
• FIG. 3 illustrates another preferred embodiment of this invention. In this case
• a fixed or dynamic emitter tip positioning system 60 is enclosed in a miniature
• the tip 32 preferably has a relatively small diameter, e.g. in the range of approximately 0.3 to 10 nanometers; single
• walled metallic-type carbon nanotube 32 serves as an atomic point source field emitter of
• the atomic point source field emitter 32 may be a multi-walled
• the support structure 64 also serves as a thermal sink and ultra-high vacuum seal to a superconducting single walled metallic-type carbon nanotube 66 of relatively larger diameter, e.g. in the range of approximately 5 to 200 nanometers, which serves both as a field emission extraction
• the electron beam 34 emerges from the field emitter 32 and is confined and focused
• the electron beam 34 penetrates the semispherical end cap 46 and emerges from the end of it. This end cap is less strongly superconducting or may not be superconducting at all. Since the momentum of the electron beam is perpendicular to
• An optional coating of material 48 may be used for purposes of vacuum sealing, enhanced mechanical strength, or enhanced superconducting focusing of the electron beam.
• electrical leads 67, 68 are connected to a voltage supply (not shown) which provides the electrical potential difference between the tip
• an optional electrical lead 69 may be connected to a voltage supply (not shown) when the optional coating of material 48 is to be utilized as the field emission extraction electrode.
• nanotubes have aspect ratios of at least about 1 : 10 to 1 : 1000.
• the material properties (such as toughness and springiness of such nanotubes) may be adapted to allow the nanotubes to
• forms of carbon nanotubes have physical properties such that they conduct electricity better than copper, they have a tensile strengths over 100 times that of steel, they become superconductors when cooled to extremely low temperatures, and they are exceptionally
• the electron transparent structures illustrated in the Figures can be formed by the carbon nanotube end caps 46 shown in Figures 2 and 3. Alternatively, or additionally, these electron transparent structures may be replaced, in part or in whole, by mechanically attaching some other ultra thin film of suitably electron transparent material to the end of an
• the micro-enclosed point source electron beam generators 10 of Figure 1 and 32 of Figures 2 and 3 may be mechanically scanned near the target to be imaged or incorporated into the tip of an atomic force microscope for the purpose of very high resolution electron microscopy and spectroscopy; or such point source electron beam generators 10 of Figure 1 and 32 of Figures 2 and 3 can be incorporated into an electron beam micro-column, such as described in "Fabrication of electron-beam microcolumn aligned by scanning tunneling microscope", Jeong- Young Park, et al, Journal of Vacuum Science and Technology A,
• Figure 21 is a schematic representation of another embodiment of an enclosed point
• tip 32 is in the shape of carbon nanotube.
• tip 32 has a relatively small diameter
• the carbon nanotube may be composed of single or multi-walled metallic-type carbon nanotube; alternatively, it may be
• the tip 32 is preferably embedded in a support structure 42, which also serves as a thermal sink and ultra-high vacuum seal to a superconducting single walled metallic-type carbon nanotube 44 of relatively larger diameter (in the range, e.g., of approximately 5 to 200 nanometers), which also serves as a field emission extraction electrode and as a miniature
• An optional coating of material 48 which may optionally be superconducting, may be used for purposes of vacuum sealing, enhanced mechanical strength, or enhanced superconducting focusing of electron beam 34.
• coating 48 may be connected to the electrical lead 43 and is then
• nanotube 44 used as an electron extraction electrode, instead of nanotube 44.
• a very thin film coating 47 comprising a conducting material, e.g. silver, copper, titanium, gold, etc. is applied to the inner surface of
• thin film coating 47 is relatively small in comparison to the conductivity of superconducting nanotube 44. As such, thin film 47 is "magnetically invisible" to electron beam 34. Thin film coating 47 has sufficient magnetic
• thin film coating 47 geometrically reduces the average effective vacuum tunneling gap, (which is the distance from a beam particle to a conductor) of superconducting nanotube 44, thus keeping electron beam 34 highly coherent and focused.
• Connector 49 is connected to a power supply (not shown), which provides an electrical potential to thin film
• Figure 22 illustrates another preferred embodiment of this invention.
• a thin, insulating film 41 is disposed between the inner surface of superconducting nanotube 44 and conductive thin film coating 47.
• Figure 23 is a schematic representation of an enclosed pico-SEM (Scanning Electron Microscope) comprising a carbon nanotube point source of electrons, which may be comprised of any of the systems shown in Figures 1, 2, 3, 21 or 22 and previously described in this specification.
• pico-SEM Sccanning Electron Microscope
• Miniature pico-SEM having working distances less than the mean free path for air, and can operate at low to medium vacuum.
• device 1350 Referring to Figure 23, device 1350
• an enclosed point source electron beam generator 1356 which is preferably a carbon nanotube point source of electrons previously described in this specification.
• Device 1350 may be used to scan external and internal cell membranes and
• Device 1350 further comprises a conically tapered
• enclosure 1354 having a proximal end 1353 and a distal end 1355.
• the proximal end of conical tapered enclosure 1354 is attached to a vacuum tube 1352 through supporting member 1358.
• Supporting member 1358 has an opening 1360, which provides a connection
• conically tapered enclosure 1354 comprises conical pipette tip target opening 1364 having a diameter ranging from about 10 nanometers
• Conical pipette tip target opening 1364 is coated with a watertight
• Device 1350 may be steered into position so that opening 1364 may become in contact with surface 1362 of specimen to be scanned by pico-SEM 1356. A portion of surface 1362 may extend into the conically tapered enclosure 1354 through opening 1364 by capillary action. The pressure inside conically tapered enclosure 1354 may be regulated by
• varying the pressure inside vacuum tube 1352 to counteract the capillary action may be adjusted by varying the backpressure provided by vacuum tube 1352.
• Figure 4 illustrates the use of a micro-enclosed point source of electrons 70, (which may consist of any of the systems shown in Figures 1 , 2, and 3) to substantially improve on other devices, such as, e.g., the device disclosed in Thomas George's "Miniature Electron Microscopes Without Vacuum Pumps", NASA Technical Brief, Vol. 22, No. 8. (JPL NEW TECHNOLOGY REPORT NPO-20335).
• a low-to-medium vacuum enclosure 72 contains
• the pressure within enclosure 72 is from about 10 "3 to 10 "6 Torr.
• An optional superconducting cylinder 74 can be used for narrowing the conical emerging
• Electrode pair 78 and electrode 80 are used for scan deflection and focus. Backscattered electron detectors 82 are placed above the observation
• Secondary and backscattered electrons may be detected either by
• Figure 5 shows how a relatively large (in the range of approximately 0.1 to 100 micron diameter) beam of electrons or positive ions 90 may be narrowed into a beam 100 by means of a superconducting channel
• Beam 90 passes through superconducting material 92 with a converging funnel
• the superconducting structure 92 may optionally be split in planes perpendicular to the funnel axis into several mutually insulating segments that are mutually electrified so as to facilitate the attraction of electrons into each successive segment.
• Figure 6 illustrates the use of superconducting carbon nanotubes 1 10, 1 12 in the range of about 0.3 to 100 nanometers in diameter constructed into a Y-junction 1 14. Because superconductivity is likely substantially reduced in the junction region itself, this region
• electron beam 120 with an ion beam 122 or with another source of electrons at a different
• One of several means of using such a system is to use the electron beam for target illumination and positioning purposes, and using the ion beam for transient milling or ion
• Y-junction assembly 130 shown in Figure 7 can be used to split an
• Additional thin film coating 144 of a superconducting material may optionally be employed
• junctions need not be
• merging junctions may be combined in practice, and may be structured so as to implement
• nano-scale electron beam analogs of fluidic technology including feedback loops.
• insulated superconducting channel segments at differing potentials. These can be used in
• nanotubes by exploiting the fabrication techniques that are used for micro-electro ⁇
• FIG. 8 illustrates one preferred use of the electron beam emitter assembly 50 of
• material 160 is a non ⁇
• conducting material e.g. Nylon-6, Nylon-66, Teflon or the like, and electrically isolates assembly 50 from assembly 88.
• material 160 is a superconducting
• microscopy devices such as e.g., Scanning Tunneling Microscopes
• the superconducting nano-channel structures of this invention comprising carbon-based nanotubes, may be used with microscopy probes. They may also operate with a miniature ultra-high vacuum enclosure with an electron-
• Free standing flexible superconducting nanometer scale tubes and fixed superconducting nanometer scale channels formed on supporting substrates may be further used for conveying coherent electron beams with energies corresponding to wavelengths of a similar order of magnitude (e.g. a few electron volts) and provides a nanometer scale electron beam analog of micron scale fiber optical systems.
• Figure 9 is a schematic representation of one embodiment of a device for guiding
• a superconducting channel 171 consisting essentially of a superconducting material 178 in the form of a tube, for guiding electron beam or other charged particle beam 180.
• beam 180 passes through
• bend 176 may be constructed with a structure having an arc of
• Bend 176 is preferably greater than zero degrees, and as much as 180 degrees in an embodiment wherein the direction of the particle beam 180 is to be
• charged particle beam guiding device 170 is an apparatus for generating and guiding a charged particle beam. Referring again to Figure 9, apparatus 170
• FIG 9 illustrates a preferred embodiment in which electron beam emitter assembly 50 is coupled to superconducting channel 171 for conveyance of coherent electron beam 180.
• electron source 50 At the proximal end 172 of channel 171 is attached electron source 50.
• An electron transparent window 173 is sealed to channel end 174 to form an ultra-high vacuum region 175 through which electron beam 180 travels. Because of the nano-scale dimensions of superconducting channel 171, ultra-high vacuum conditions may be achieved within region 175.
• electron transparent membrane or window 173 may be either substantially planarj or a semi-spherical cap, and of the materials previously described in this specification and shown in Figures 1, 2, and 3.
• Figure 1OA is a schematic representation of a side view of a superconducting nano-
• Figure 1 OB is a top view of the representation of Figure 1 OA taken
• Figures 1OA and 1OB illustrate a preferred embodiment in which 2-D, "2.5-D", and 3-D superconducting nano-channels may be fabricated on a
• assembly 300 comprises substrate 302 onto which
• superconducting material 304 is deposited by means known in the art. Superconducting
• nano-channels 306 and 308 may be formed using lithography or stereo-lithography, or other
• additional layers of superconducting material may be deposited on
• Electron beams or other charged particles may be guided and
• Superconducting material 304 may comprise C60 hybrids or boron
• Figures HA, HB, and HC are schematic representations of embodiments of superconducting nano-channels having nano-scale superconducting rods.
• I IC illustrate preferred embodiments in which a superconducting nano-channel suitable for guiding and manipulating sub-nanometer-scale electron beams and other charged particles may be formed by geometrically arranging nano-scale superconducting rods or wires around a central region.
• rods 352 are
• Rods 352 are arranged in physical contact with one another, around center rod 354. Referring to Figure 1 IB, central rod 354 is removed to form a central superconducting nano-channel 356 bounded by superconducting rods 352. Electron beams or other charged particles may flow through channel 356.
• superconducting rods 352 may have cross sections other
• Superconducting rods 352 may be coated with
• Figure 12 is a schematic representation of a superconducting nano-channel having
• Figure 12 illustrates a preferred embodiment in which a layer of superconducting material 404 is deposited on substrate 402. Referring to Figure 12, a layer of
• non-conducting material 406 is deposited on top of superconducting layer 404. Another layer
• superconducting channels 410, 412, and 414 may be formed using conventional lithographic techniques. The relative degree of confinement of each superconducting nano-channels 410, 412, and 414 may be geometrically modulated to suit any particular application. For example, superconducting nano-channels 410 and 414 would be more strongly confining than superconducting nano-channel 412, due to the greater relative enclosure of superconducting material. On the other hand, charged particles 416 traveling through superconducting channel 412 will experience Meissner effect repulsion originating from the four quadrants 420, 422,
• Figures 13A and 13B are schematic representations of embodiments of a superconducting nano-channel split in the axial direction, i.e. parallel to the central axis of
• FIGS 13A and 13B illustrate a preferred embodiment in which the superconducting nano-channel is a superconducting nano-cylinder. Referring to Figure 13 A,
• superconducting nano-cylinder 450 is axially split into two half-cylinders 452 and 454
• a layer of conductive material 456 and 458 may be applied to
• a layer of insulating material 462 and 464 separates the inner
• superconducting nano-cylinder 450 may be
• superconducting channel 460 in a readily variable and electronically controlled fashion.
• Figure 14 is a schematic representation of a superconducting nano-channel connected
• assembly 750 in which
• superconducting nano-wires are used to make superconducting loops 754, 756, and 758,
• baseball seam curves, U-shaped loops, etc. may be configured as superconducting nano-
• These shapes may additionally be electrically charged or magnetized (by running electrical currents through them), thereby affording a multiplicity of characteristic particle optical effects.
• electrically charged or magnetized by running electrical currents through them
• nano or picobeam trajectories such shapes may be subject to electrostatic charging, which
• Such shapes may have predetermined discharge rates, and may be cross-coupled to other shapes.
• the anode currents of electrically split anodes in the path of deflectable charged picobeams may be used to differentially drive various electric or magnetic superconducting shapes, thus influencing the trajectory of the same or other charged nano or picobeams.
• the use of flexible shapes or flexible mounts adds another dimension of possibilities, both for simple deflection and for multiple mechanical resonance modes, especially since even very small motions can have a geometrically magnified leverage effect
• Figures 15A, 15B, and 15C are schematic representations of embodiments of superconducting nano-channels split into unequal portions.
• Figures 15A and 15B illustrate a
• a superconducting cylinder 900 e.g., a superconducting
• nano-tube which is split into unequal portions along its length by straight split lines 906 and
• Figure 15B is a perspective view
• superconducting cylinder 900 is split into a major superconducting segment 902 and a minor superconducting segment 904, which have different arc displacements but are of the same radius of curvature.
• Non-superconducting material in gaps 906 and 908 may be used to hold
• Figure 15C illustrates another embodiments in which a superconducting cylinder 950 is split into a major superconducting segment 902 and a minor superconducting segment 904 by non-straight split lines 910 and 912.
• Superconducting segment 952 and a minor superconducting segment 954 have different sizes and different shapes.
• Non-superconducting material may be used to hold superconducting segments 952 and 954 together as described previously.
• Figure 16A - 16D are schematic representations of embodiments of merging superconducting nano-channels.
• superconducting nano-channel approximations as described in the embodiment depicted in Figure 14 may also be merged together.
• Merged superconducting nano-channels may be used to mix injected charged particles. They may also be used as transport assemblies for charged particles, or to modulate one charged particle beam with another. They may also be used to dynamically switch the
• FIG. 1020 shows a sectional view of the merged superconducting nano-channels
• charged particle beams 1014 and/or 1016 may have their exit trajectories switched between superconducting nano-channels 1006 and 1008 to emerge as charged particle beams 1018 or 1020.
• the walls of superconducting assembly 1000 as shown in Figure 16A may be partitioned into nearly contiguous but electrically isolated segments, thus negating to need to have separate electrical conductors 1030 and 1032.
• Figure 16C illustrates a preferred embodiment in which superconducting rods made of superconducting nano-wires are used to form an approximation to a superconducting nano- tube, as previously described in the embodiments shown in Figures 1 IA - 1 1C.
• superconducting nano-channel 1002 (see Figure 16A) is approximated by superconducting rods 1042, 1044, 1046, and 1048, to define superconducting nano-channel 1050.
• superconducting nano-channel 1004 is approximated by superconducting nano-rods 1052, 1054, 1056, and 1058 to define superconducting nano-
• Electron beams or other charged particles traveling through superconducting are Electron beams or other charged particles traveling through superconducting
• nano-channels 1050 and 1060 may be guided and manipulated, taking advantage of the Meissner effect (repulsion forces).
• line 16B-16B (as shown in Figure 16A) is replaced by the approximation defined by superconducting nano-channel 1062, which is created by superconducting rods 1042, 1044,
• An electrical voltage provided by a power source may be applied to
• Superconducting nano-channel 1062 thus becomes a switching region where electron beams or other charged particles traveling through superconducting nano-channel 1062.
• particles may be guided to the desired exit channels as described in the embodiment shown in Figure 16A.
• Figure 17 is a schematic representation of a superconducting nano-channel Y- junction.
• Figure 17 illustrates a preferred embodiment in which superconducting glass
• capillaries may be used to guide and manipulate electron beams and other charge particles.
• Superconducting glass capillaries, with exit ports as small as about 10 nanometers, have an advantageously amorphous and anatomically smooth surface. They may be used for merging, for example, x-rays (both hard x-rays and soft x-rays) and electron beams (both nano and
• Superconducting glass capillaries may be able to produce geometric beam energy concentration gains on the order of 1000 or more.
• a Y-shaped glass capillary 1100 having its inner surface coated with a glass layer 1 1 14, and having its outer surface coated with a layer
• Superconducting glass capillary 1 100 comprises entry
• beam 1 102 is introduced into port 1104 and is guided by glass layer 1 1 14, while a
• intermittent electron beam or other charged particle beaml lO6 is introduced
• Charged particle beam 1 106 is introduced at a suitable angle relative to x-ray beam 1102 in order to minimally impact and minimally intercept the x-ray beam 1 102.
• both beams 1102 and 1106 After reaching the intersection area 1110 (i.e. shared space), both beams 1102 and 1106 begin.
• Both beams 1 102 and 1 106 are controllably turned ON and OFF by suitable means (not shown) to select which beam (mode) is in operation.
• a guide and manipulate a plurality of beams may be used for multi-mode imaging, microanalysis, lithography and stereolithography.
• An application of how this mode switching may be used to perform two distinct functions almost simultaneously will be described as follows: in a first mode, charged particles might be guided and manipulated for imaging and identifying the topography or other feature of a substrate for subsequent x-ray irradiation by a second mode.
• electronic beams or other charged particle beams may be modulated over the shared space with intensely concentrated x-rays (or vice versa, with suitable adjustments of electron energy and nano-channel diameter). Additional interactions
• Figure 18 is a schematic representation of a superconducting nano-channel with internal superconducting wires. Figure 18 illustrates a preferred embodiment in which
• superconducting nano-channels have different diameters at their respective ends.
• the beam input end has a larger diameter than the beam exit
• the larger diameter allows the superconducting nano-channels to internally accommodate a plurality of superconducting wires defining coaxial structures, which may be arranged in a straight, helical, or other suitable configurations.
• a power source (not shown) may be applied to the coaxial structures to modulate the axial and radial velocity components of electron beams or other charged particles
• superconducting nano-channel 550 is shown having a beam input end 552 and a beam exit end 554.
• the diameter of beam input end 552 is larger than the diameter of beam output end 554.
• Beam input end 552 accommodates a coaxial structure comprising superconducting nano-wires 560.
• superconducting nano-wires 560 may be used to modulate the axial and radial velocity components of electron beam or other charged particle beam 558 traveling through central channel 556.
• Figure 19 is a schematic representation of a superconducting nano-channel as a field
• FIG. 19 illustrates a preferred embodiment in which superconducting nano- channels are used as volcano field ionizers for magnetic nano-particles.
• Volcano field ionizers make use of a relatively small diameter hollow cathode tube for injecting materials into a region with a very high electric field gradient, which subsequently ionizes the injected
• superconducting nano-channel 606 is shown having an optional bend region 614.
• Superconducting nano-channel 606 comprises beam input end 610
• a beam of magnetic nano-particles 608 is injected into the superconducting nano-channel 606 through beam input end 610 and exits through nozzle
• Electrodes 602 and 604 provide a large electrical potential difference between electrodes
• Electrodes 602 and 604 Said large electrical potential difference ionizes magnetic particles 608 in the vicinity of the high electric field region 616 of nozzle 612. Electrodes 602 and 604
• superconducting nano-channels may be used to focus and guide traveling antiprotons for medical applications, such as killing tumors.
• insulation may be used for chilling the superconducting nano-channel.
• a single lower velocity beam could be delivered directly to the ultimate target by a thin superconducting nano- or
• a low velocity beam could be more readily deflected (steered to target) at the tumor site by micro-deflection coils or micro-deflection electrodes than high velocity beams. Since the matter/anti-matter interaction region would thereby be highly localized, so too would the relative density and distribution of (e.g., gamma-ray) radiation of the anti-proton/proton annihilation.
• gamma-ray gamma-ray
• Figure 2OA - 2OC are schematic representations of a superconducting nano-channel as a component of an acoustic wave detector system.
• Figures 2OA - 2OC illustrate a preferred embodiment in which superconducting nano-channels may be used as integral
• charged particle beam 1254 is injected and travels through
• superconducting nano-channel 1252 which is attached to support 1256.
• An end cap 1266 is used to cap superconducting nano-channel 1252 and to keep vacuum within region 1268 of superconducting nano-channel 1252. In the absence of acoustic waves, superconducting
• nano-channel 1252 remains motionless.
• acoustic wave 1258 propagating in the direction shown by arrow 1260 will cause superconducting nano-channel 1252 to oscillate back and forth, thus deflecting the charged particle beams 1262 and 1264 as they exit superconducting nano-channel 1252.
• Position sensitive beam detectors may be used to detect
• deflected beams 1262 and 1264 as they exit superconducting nano-channel 1252.
• These superconducting nano-channel configurations which take advantage of deflected charged particles, may be used in analog signal processing devices, high-sensitivity and high- bandwidth nano-vibration sensors, pico-beam scanning and chopping operations, and the
• charged particles may be modulated, may be suitably mechanically loaded and mechanically driven for generating charged particle scanning patterns.
• the superconducting nano-channel structures of this invention comprising carbon-
• nanotubes or other types of nanotubes may be used with microscopy probes. They may be used with microscopy probes. They may be used with microscopy probes. They may be used with microscopy probes. They may be used with microscopy probes. They may be used with microscopy probes. They may be used with microscopy probes. They may be used with microscopy probes. They may be used with microscopy probes. They may be used with microscopy probes. They may be used with microscopy probes. They may be used with microscopy probes. They may be used with microscopy probes. They may be used with microscopy probes. They may be used with microscopy probes. They may be used with microscopy probes. They may be used with microscopy probes. They may be used with microscopy probes. They may be used with microscopy probes. They may be used with microscopy probes. They may be used with microscopy probes. They may be used with microscopy probes. They may
• imaging and detecting devices but not limited to, imaging and detecting devices.
• Figure 24A is a cross-sectional schematic representation (not to scale) of one
• FIG. 24B is a top view of the solid state sub-nanometer-scale electron beam emitter of Figure 24A, taken along the line 24B - 24B of Figure 24A.
• emitter 200 is formed on a substrate 201, preferably a silicon chip substrate.
• Emitter 200 is a multi-layered structure
• nano-tip electron emitter and tunnel emission junction 202 formed on substrate 201 , initial electron beam extraction electrode 204, "nano-sandwich Einzel lens” electrode 230, and topmost protective layer 220.
• Nano-tip electron emitter 202 is formed on substrate 201, and is preferably an atomic point emitter, or nearly atomic point emitter.
• "Nano-sandwich Einzel lens” electrode 230 functions as an electron beam lens (i.e. an electrostatic focusing lens), and comprises a lower metal membrane and primary electron beam acceleration electrode 232, annular metal electrode 240, and upper metal membrane electrode 234.
• an electron beam lens i.e. an electrostatic focusing lens
• Topmost protective layer 220 is preferably a nano- layer of diamond, or other suitable electron-transparent material such as silicon nitride, or aluminum oxide. Similar electron transparent material is also used in the spacing of nano-
• nano-tip emitter 202 being one preferred material due to the ruggedness, heat conductivity, and negative electron affinity thereof. In operation, electrons emitted from nano-tip emitter 202 are emitted through
• emitter 200 is fabricated with layer 203 between about 10 and
• Emitter 200 is shown in Figures 24A and 24B
• a substantially cylindrical diameter emitter 200 is provided having a diameter of between about 10 and about 1 ,000 nanometers.
• Electrodes 204, 232, 240, and 234 are preferably formed of metallic films and are preferably between about 1 and about 10 nanometers thick.
• annular electrode has an opening 297 of between about 10 and about 100 nanometers in diameter.
• electrodes 204, 232, 240, and 234 are formed of carbon graphene
• nano-tip emitter 202 is formed in a substantially conical shape
• embodiment is fabricated from polycrystalline platinum.
• Other tip shapes may be provided
• protective layer 220 is between about 1 and about 10 nanometers, and more preferably between about 2 and about 5 nanometers.
• layer 205 is omitted, and electrodes 232 and 204 are merged into a single electrode that serves a dual function of extraction electrode and the electrode of an electrostatic lens. In another embodiment of this case involving extremely small dimensions
• the evacuated region 297 is filled with an insulating electron transparent material, which is also used for layers 233 and 235.
• the electrostatic lens subsystem is omitted, and protective layer
• sharply pointed field emission electrodes in an evacuated environment is one of the most common means of generating electron beams for applications requiring high beam quality and very fine focusing.
• the sharp tip geometry leads to a highly localized and intensely concentrated electric field gradient, which makes it possible to extract an electron beam with moderate applied voltages.
• microcolumns Miniature electron beam sources known as microcolumns have been studied.
• microcolumns in such studies are on the order of microns (10 *6 meters).
• Microcolumn types of structures have also been considered for miniature scanning electron microscopes; see for example, Thomas George (1998). "Miniature Electron Microscopes Without Vacuum Pumps", NASA Technical Brief, Vol. 22, No. 8.
• the nano-emitter system of the present invention system may be regarded as a dramatically further miniaturized microcolumn that advantageously utilizes and/or results from certain nano-scale electronic properties of materials. Accordingly, the applicant believes that the use of the nano-emitter system of the present invention in such electron beam lithography and electron microscopy systems will provide superior performance in the respective applications thereof.
• nano-emitter system 200 of Figure 24A provide significant improvements to these previously disclosed microcolumn systems.
• One embodiment is directed to the nano-tip emitter 202, wherein instead of using a relatively crude (on the
• an atomic point emitter such as a perfect
• Such tungsten and carbon nanotubes emitter tips have been described previously in this specification, with regard to the embodiments of enclosed point source electron beam generators shown in Figures 1, 2, 3, and 21. As indicated in the previously cited papers coauthored by H. W. Fink, such atomic point field emitters operating in ultra-high vacuum may be used to generate exceptionally narrowly focused electron beams
• Nano-emitter tips formed from certain carbon nanotubes are almost as effective in generating such focused electron beams.
• an emitter tip can be degraded by reverse ion bombardment, particularly in applications wherein such a tip is disposed in an ultra-high vacuum chamber, rather than in a solid state device.
• these emitters may be useful in solid state nano-emitters of the present invention because at certain electron energies, certain insulating and metallic nano- layers formed therein are effectively electron-transparent.
• the crucial emitting tip is protectively encapsulated, such as e.g. the encapsulation of tip 202 in layer 203 of emitter 200 of Figure 24 A.
• the entire emitting tip is protectively encapsulated, such as e.g. the encapsulation of tip 202 in layer 203 of emitter 200 of Figure 24 A.
• the entire emitting tip is protectively encapsulated, such as e.g. the encapsulation of tip 202 in layer 203 of emitter 200 of Figure 24 A.
• the entire emitting tip is protectively encapsulated, such as e.g. the encapsulation of tip 202 in layer 203 of emitter 200 of Figure 24 A.
• the entire emitting tip is protectively encapsulated, such as e.g. the encapsulation of tip 202 in layer 203 of emitter 200 of Figure 24 A.
• emitter column 250 and electrostatic focusing lens 230 (or lenses) therein is solid state, wherein the total required electron-beam path length from the distal end of nano-tip 202 to
• the surface 221 of protective layer 220 is sufficiently reduced.
• nano-emitter system 200 of the present invention there is
• apparatus comprising an electron source with a needle and a membrane-like extraction
• metal-vacuum-metal quantum tunneling phenomenon is made by reducing the emitter-to-
• the emitter-to-extractor the emitter-to-extractor
• electrode distance 298 of the device is about 1 nanometer.
• electron-transparent metal membrane electrodes are incorporated into system 200 such that
• VMEDs vacuum micro-electronic devices
• the very small probe size of the nano-emitter minimizes the beam
• Electron beams with about 1 milli-radian convergence angle are needed for good depth of field.
• aberrations in electrostatic lenses tend to decrease with decreasing lens size, and hence the extremely small size of the nano-sandwich Einzel lens of the nano-emitter is a lens with minimal aberrations. Operation of nano- electron-beam components at very low voltages allow operation in air without causing
• an electron lens or lenses are a first electron lens or lenses.
• FIG 25 is a cross sectional schematic diagram of a conventional Einzel electrostatic focusing lens for focusing an electron beam passing therethrough.
• lens 330 comprises a first annular electrode 340, above and below which are disposed second annular electrode 334, and third annular electrode 332 respectively.
• a focusing voltage V f is applied to electrode 340, and electrodes 332 and 334 are at ground (zero) potential.
• Electrons that are discharged from an electron beam source (not shown) follow an overall general trajectory through the lens as indicated by arrow 399. Such electrons enter lens 390 along trajectories 396 that are divergent in region 395.
• Figure 26A is a detailed cross sectional view of one embodiment of a "nano-sandwich
• lens 230 comprises annular metal electrode 240, above and below which are disposed upper
• a focusing electrode 334 In one mode of operation used for focusing an electron beam, a focusing
• Electrons that are discharged from emitter tip 202 follow an overall general trajectory through the lens as indicated by arrow 299. Such electrons enter
• lens 290 along trajectories 296 that are divergent in region 295.
• the electrostatic effect of electrodes 240, 232, and 234, as indicated by electric field lines 293 result in the convergence of the electron trajectories 296 in region 294 and the focusing of the electron beam at focal
• the extremely small scale of the structure of lens 230 provides it with significant advantages over conventional Einzel electrostatic lenses.
• the geometry of lens 230 results in high structural strength thereof.
• the operation of lens 230 can be varied to provide both focus and defocus (convergent and divergent) modes, unlike conventional Einzel lenses, which can only focus charged particles.
• the extremely compact size of the "nano-sandwich" lens 230 results in acceptable electron beam focusing performance when using a solid state sandwich structure as indicated in Figure 26A, and in Figure 24A for the nano-electron-beam emitter 200 previously described in this specification.
• Such a structure simplifies mass production of the lens and emitter devices, and also facilitates the stacking of additional lens stages, i.e. the forming of
• lens 230 of Figure 26A may be formed with a central
• Figure 26B is an axial cross
• lens 230 comprises a unitary annular metal electrode 240 having an
• Figure 26C is an axial cross sectional view of
• central electrode 241 comprises segments 242, 244, 246, and 248.
• these segments may be set to different voltages, either statically or dynamically, in order to provide electron beam focusing, defocusing, and/or steering away from the central axis of the lens. It will be
• capabilities may also enable the mass production nano-scale scanning electron microscopes with routine atomic resolution.
• the extremely compact size of the solid-state nano-electron-beam emitters and lenses of the present invention also enable them to be fabricated on the moving parts of micro-
• Arrays of nano-electron-beam nano-lenses of the present invention may be manufactured and used independently of nano-electron-beam sources, for purposes of either nano-lithography or nano-microscopy with more conventional electron
• Such nano-lens arrays may also serve as a new type of photomask that may subsequently be used for fabricating replicas of itself, and then subsequently fabricating
• ultraviolet light driven processes e.g., photoemission charging, and/or
• emitter tip 202 is first formed on substrate 201 by depositing a C 60 buckyball.
• the nano-emitter tip 202 may be a capped carbon nanotube.
• a controlled deposition of a nano-layer of diamond, silicon nitride, or aluminum oxide over the emitter is used to form layer 203.
• a nano-layer of a suitable refractory metal for the extraction electrode 204 is deposited next, followed by another nano- layer 205 of the underlying material.
• Accelerating electrode 232 which also serves as the
• cover layer 233 are formed in like manner.
• the annular nano-sandwich electrode In the preferred fabrication process embodiment, the annular nano-sandwich electrode
• 240 is preferably formed by exploiting the underlying emitter 202 for a highly localized form of "backwards" or “reverse” electron beam nano-lithography.
• a conventional electron-beam resist is used, i.e., deposited, exposed, and developed, to form an image of electrode 240, with the difference that the electron beam is exposing or writing the image of electrode 240 from the substrate 201 side rather than from the surface 221 side. This is an automatically self-aligning process, and an inherently parallel production process.
• the nano-sandwich-Einzel-lens structure may be operated in reverse for emitter "fine tuning", i.e. adjusting the tunnel gap between the atomic-point
• curing of support material using ultraviolet light is performed following precise positioning of emitter 202 and the extraction grid.
• the emitter tips comprises tungsten-tipped carbon nanotubes using
• - Emitters comprised of quantum wells, quantum dots, and/or superlattice structures.
• the very small size of the electron source and electron optics thereof enables the very small size of the electron source and electron optics thereof enables the very small size of the electron source and electron optics thereof enables the very small size of the electron source and electron optics thereof enables the very small size of the electron source and electron optics thereof enables the very small size of the electron source and electron optics thereof enables the very small size of the electron source and electron optics thereof enables the very small size of the electron source and electron optics thereof enables the
• non-point, non-beam tunnel emitters may be applied in a non ⁇ uniform radially varying way to function as a lens element involving pairs of closely spaced nano-emitter electrodes of the present invention.
• thin-film electrodes and preferably for the central annular electrode as well.
• doped diamond At electron energies where metal films are relatively opaque to electrons, it may be advantageous to use doped diamond, especially in cases where diamond is already being used as the inter-
• nano-emitters of the present invention may also apply to provide tunnel emission cooling systems; see for example, U.S. Patent 6,417,060 of Tavkhelidze et al.,
• nano-emitters of the present invention may be eliminated by factoring the tunnel gap from the collection electrode using a multitude of individual point nano-emitters of the present invention. This also provides a system having much greater flexibility for implementing alternative geometric configurations.
• the nano-emitters of the present invention may also be used to provide exceptional integral cooling of other emitter systems being driven at much higher than normal power
• Cooling emitter arrays may be arrayed in concentric circles to provide cryogenic cooling of capillary superconducting tubes that exploit the Meissner effect for the propagation of particle beams for various medical and scientific
• Such a fabrication involves the use of thin layers of bimetallic materials for which post- deposition cooling induces powerful localized buckling stresses in order to form nano-
• NiTi Nitinol
• integrated circuit chips with a large array of nano- field-emitters of the present invention may make use of electron-beam induced carbon deposition processes (among others) instead of the conventional chip-to-chip bonding processes. Dramatically smaller bonding pads with much smaller interconnections may be used. This application is somewhat analogous to a neuron growing a dendritic connection.
• the growing connection from a facing chip ultimately makes contact with
• the nanosandwich-Einzel lens may be omitted.
• many off-axis "dendrites" are grown
• micro-electromechanical (MEMS) chips with an
• nano-emitters of the present invention are electron beam

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